运行这个程序需要预先设置栈内存和文件描述符上限, 否则运行失败
ulimit -n 16384
ulimit -s 4096

文件名:server.c
编译: gcc server.c -Wall -O2 -pthread -o server
程序源码如下(请自行编辑宏定义SERVER_IP为自己的IP):


/*Linux 2.6 x86_64 only*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>

#include <sys/epoll.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <pthread.h>

#define THREAD_MAX 4096
#define LISTEN_MAX 5000
#define SERVER_IP "192.168.1.103"

typedef struct {
char ip4[128];
int port;
int fd;
} LISTEN_INFO;

//服务器参数
static LISTEN_INFO s_listens[LISTEN_MAX];

//线程池参数
static unsigned int s_thread_para[THREAD_MAX][8];//线程参数
static pthread_t s_tid[THREAD_MAX];//线程ID
pthread_mutex_t s_mutex[THREAD_MAX];//线程锁


//私有函数
static int init_thread_pool(void);
static int init_listen4(char *ip4, int port, int max_link);

//线程函数
void * test_server4(unsigned int thread_para[]);

int main(int argc, char *argv[])//客户端驱动
{
//临时变量
int i, j, rc;

int sock_listen; //监听套接字
int sock_cli; //客户端连接
int listen_index;

int epfd;
int nfds;
struct epoll_event ev;
struct epoll_event events[LISTEN_MAX];

socklen_t addrlen; //地址信息长度
struct sockaddr_in addr4; //IPv4地址结构

//线程池初始化
rc = init_thread_pool();
if (0 != rc) exit(-1);

//初始化服务监听
for(i = 0; i < LISTEN_MAX; i++) {
sprintf(s_listens[i].ip4, "%s", SERVER_IP);
s_listens[i].port = 8000 + i;
//创建监听
rc = init_listen4(s_listens[i].ip4, s_listens[i].port, 64);
if (0 > rc) {
fprintf(stderr, "无法创建服务器监听于%s:%d\r\n", s_listens[i].ip4, s_listens[i].port);
exit(-1);
}
s_listens[i].fd = rc;
}

//设置集合
epfd = epoll_create(8192);
for (i = 0; i < LISTEN_MAX; i++) {
//加入epoll事件集合
ev.events = EPOLLIN;
ev.data.u32 = i;//记录listen数组下标
if (epoll_ctl(epfd, EPOLL_CTL_ADD, s_listens[i].fd, &ev) < 0) {
fprintf(stderr, "向epoll集合添加套接字失败(fd =%d)\r\n", rc);
exit(-1);
}
}


//服务循环
for( ; ; ) {
//等待epoll事件
nfds = epoll_wait(epfd, events, LISTEN_MAX, -1);
//处理epoll事件
for(i = 0; i < nfds; i++) {
//接收客户端连接
listen_index = events[i].data.u32;
sock_listen = s_listens[listen_index].fd;
addrlen = sizeof(struct sockaddr_in);
bzero(&addr4, addrlen);
sock_cli = accept(sock_listen, (struct sockaddr *)&addr4, &addrlen);
if(0 > sock_cli) {
fprintf(stderr, "接收客户端连接失败\n");
continue;
}
//查询空闲线程对
for(j = 0; j < THREAD_MAX; j++) {
if (0 == s_thread_para[j][0]) break;
}
if (j >= THREAD_MAX) {
fprintf(stderr, "线程池已满, 连接将被放弃\r\n");
shutdown(sock_cli, SHUT_RDWR);
close(sock_cli);
continue;
}
//复制有关参数
s_thread_para[j][0] = 1;//设置活动标志为"活动"
s_thread_para[j][1] = sock_cli;//客户端连接
s_thread_para[j][2] = listen_index;//服务索引
//线程解锁
pthread_mutex_unlock(s_mutex + j);
}//end of for(i;;)
}//end of for(;;)

exit(0);
}

static int init_thread_pool(void)
{
int i, rc;

//初始化线程池参数
for(i = 0; i < THREAD_MAX; i++) {
s_thread_para[i][0] = 0;//设置线程占用标志为"空闲"
s_thread_para[i][7] = i;//线程池索引
pthread_mutex_lock(s_mutex + i);//线程锁
}

//创建线程池
for(i = 0; i < THREAD_MAX; i++) {
rc = pthread_create(s_tid + i, 0, (void *)test_server4, (void *)(s_thread_para[i]));
if (0 != rc) {
fprintf(stderr, "线程创建失败\n");
return(-1);
}
}

//成功返回
return(0);
}

static int init_listen4(char *ip4, int port, int max_link)
{
//临时变量
int sock_listen4;
struct sockaddr_in addr4;
unsigned int optval;
struct linger optval1;

//初始化数据结构
bzero(&addr4, sizeof(addr4));
inet_pton(AF_INET, ip4, &(addr4.sin_addr));
addr4.sin_family = AF_INET;
addr4.sin_port = htons(port);

//创建SOCKET
sock_listen4 = socket(AF_INET, SOCK_STREAM, 0);
if (0 > sock_listen4) return(-1);

//设置SO_REUSEADDR选项(服务器快速重起)
optval = 0x1;
setsockopt(sock_listen4, SOL_SOCKET, SO_REUSEADDR, &optval, 4);

//设置SO_LINGER选项(防范CLOSE_WAIT挂住所有套接字)
optval1.l_onoff = 1;
optval1.l_linger = 60;
setsockopt(sock_listen4, SOL_SOCKET, SO_LINGER, &optval1, sizeof(struct linger));

if (0 > bind(sock_listen4, (struct sockaddr *)&addr4, sizeof(addr4))) {
close(sock_listen4);
return(-1);
}

if (0 > listen(sock_listen4, max_link)) {
close(sock_listen4);
return(-1);
}

return(sock_listen4);
}


void * test_server4(unsigned int thread_para[])
{
//临时变量
int pool_index; //线程池索引
int sock_cli; //客户端连接
int listen_index; //监听索引

char buff[32768]; //传输缓冲区
char *p;
int i, j, len;

//线程脱离创建者
pthread_detach(pthread_self());
pool_index = thread_para[7];

wait_unlock:

pthread_mutex_lock(s_mutex + pool_index);//等待线程解锁

//线程变量内容复制
sock_cli = thread_para[1];//客户端连接
listen_index = thread_para[2];//监听索引

//接收请求
len = recv(sock_cli, buff, 32768, MSG_NOSIGNAL);

//构造响应
p = buff;
//HTTP头
p += sprintf(p, "HTTP/1.1 200 OK\r\n");
p += sprintf(p, "Content-Type: text/html\r\n");
p += sprintf(p, "Connection: closed\r\n\r\n");
//页面
p += sprintf(p, "<html>\r\n<head>\r\n");
p += sprintf(p, "<meta content=\"text/html; charset=UTF-8\" http-equiv=\"Content-Type\">\r\n");
p += sprintf(p, "</head>\r\n");
p += sprintf(p, "<body style=\"background-color: rgb(229, 229, 229);\">\r\n");

p += sprintf(p, "<center>\r\n");
p += sprintf(p, "<H3>连接状态</H3>\r\n");
p += sprintf(p, "<p>服务器地址 %s:%d</p>\r\n", s_listens[listen_index].ip4, s_listens[listen_index].port);
j = 0;
for(i = 0; i < THREAD_MAX; i++) {
if (0 != s_thread_para[i][0]) j++;
}
p += sprintf(p, "<H3>线程池状态</H3>\r\n");
p += sprintf(p, "<p>线程池总数 %d 活动线程总数 %d</p>\r\n", THREAD_MAX, j);
p += sprintf(p, "</center></body></html>\r\n");
len = p - buff;

//发送响应
send(sock_cli, buff, len, MSG_NOSIGNAL);

//释放连接
shutdown(sock_cli, SHUT_RDWR);
close(sock_cli);

//线程任务结束
thread_para[0] = 0;//设置线程占用标志为"空闲"
goto wait_unlock;

pthread_exit(NULL);
} 

